Bioprinted Recombinant Human-Collagen-Based In Vitro Skin Models for Assessing Effects of Nano-ZnO on Dermis

This study developed bioprinted in vitro 3D skin models using methacrylated recombinant human collagen-based bioinks to assess the effects of nano-zinc oxide (nano-ZnO) on the dermis. The models, which mimic child and adult skin by adjusting collagen I/III ratios, demonstrated excellent printability, mechanical stability, and cell survivability, with viabilities ranging from 78% to 82%. Gene expression analysis revealed that nano-ZnO significantly modulates genes related to apoptosis, inflammation, and oxidative stress, with the adult model showing enhanced anti-apoptotic and anti-inflammatory capacities. These findings highlight the potential of these models for evaluating cosmetic and therapeutic agents, as well as for skin tissue engineering and toxicity testing.